JPH0398416A - Open-phase protective device for circuit breaker - Google Patents

Abstract

PURPOSE:To conduct reset positively by installing a rectifying device in series with an output contact closed by an open-phase protective circuit in the direction that conduction between the open-phase protective circuit and the output contact is prevented. CONSTITUTION:When open phase is generated in a circuit breaker (not shown), an output contact 7 is closed, all phase of the circuit breaker is opened, and a rectifying device 10 is directed in the forward direction, thus preventing trouble on operation. However, all phases of the circuit breaker are opened, all phase of first and second auxiliary negative contacts 42, 51 are opened, and since the rectifying device 10 is mounted in series in the opposite direction to a circuit in a path from a power supply P on the positive side to a power supply N on the negative side through a diconnection monitor circuit 9, the output contact 7 and an open-phase protective circuit 6, conduction is blocked. Accordingly, the output contact 7 and the open-phase protective circuit 6 are reset positively regardless of the distribution of a resistance value in the circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an open-phase protection device (hereinafter referred to as an open-phase protection device) for a polyphase circuit breaker having a drive device for each phase.

[Conventional technology]

Figures 2 and 3 are circuit diagrams of a conventional open-phase protection device disclosed in, for example, Japanese Patent Publication No. 1-19207. (not shown). In Figure 2, (1) is the switchboard circuit, {■ is the trip signal circuit installed in the switchboard number circuit (1), and is used to send trip signals when an accident occurs. (21).
22) is the contact point of the Hotan 2E device, P is the power supply, and indicates the positive pole of the operating power supply. (3) is the circuit breaker operating circuit, (4) is the tripping circuit, (41) is the tripping coil provided for each phase, and (42) is the first auxiliary contact for the circuit breaker. The circuit is opened in the open state, and jumps in the closed state, and is connected in series with a tripping coil (4l) for each phase. The tripping coil (41) and the first auxiliary contact (42) constitute a tripping circuit {4}. (The phrase is an open phase detection circuit,
(5l) is the second auxiliary contact that performs the same operation as the first auxiliary contact, (52) is the third tdi 'Xi) contact that performs the opposite operation to the second auxiliary contact (5l); 2 and 3rd auxiliary contacts (51). (52) are each connected in parallel for three phases, and then connected in series with each other to form an open phase detection circuit (5).(6) is an open phase protection circuit;
1). (62) are the coil of a time-limited relay (hereinafter referred to as a time-limited continuator) and the contact (hereinafter referred to as a time-limited contact), respectively.
Then, the time-limited continuator (6l) is energized and the time-limited contact (62) closes after a certain period of time. (63) and (7) are the coil of the auxiliary relay (hereinafter referred to as the auxiliary relay) and the output contact, respectively. When the auxiliary relay (63) is energized, the output contact (7) closes. Time-limited contact (62) and auxiliary relay (
63> are connected in series and connected in parallel with a time-limited electric device (6l), which together form an open phase protection circuit (6). (81 is the pressure relay contact, which opens due to a drop in the pressure of the gas sealed in the circuit breaker, etc., and prevents the circuit breaker from opening in such a state.N is the power supply, and the negative terminal of the operating power supply The output contact (7) and the tripping circuit (4) are connected in series for each phase, and the pressure relay contact (8) is connected in series for all phases. and the phase loss protection circuit (6) are connected in series,
The output contact (7) and the phase loss detection circuit (P) are connected to the power supply P, and the pressure relay (8) and the phase loss protection circuit (6) are connected to the power supply N, and these constitute the operation circuit (3). The trip signal circuit (2) is connected in parallel with the output contact (7).

Next, we will explain the operation. Consider a case where when trying to close a three-phase circuit breaker in an open state, only one phase, for example, phase A, does not close. Open-phase detection circuit {9 is in a closed circuit state as a whole, that is, in an operating state, and electricity is supplied from the power supply P to the time limit relay (6!) via the open phase detection circuit (51). When the open phase state continues for a certain period of time, the time limit contact (62) closes. The auxiliary relay (63) is energized, and the open-phase protection circuit (6) is activated.The auxiliary relay (63) is energized to close the output contact (7).In the tripping circuit (4) , 1st
The B and C phases of the auxiliary contact (42) are closed, and the pressure relay contact (8) is also closed, so the output contact (
7), the B phase and C phase of the tripping coil (4l) are energized, and the circuit breaker opens. Note that the first auxiliary contact (42
) remains open, so the tripping coil (41
) is not energized, but the A phase of the circuit breaker is not originally closed, so all three phases are open. Second,
The third auxiliary contacts (51) and (52) are open and closed for all phases, respectively, and therefore the open phase detection circuit is in an open state as a whole, and the current to the time-limiting relay (6l) is cut off. ．． Therefore, the time-limited contact (62) is opened and the Kamisuke relay (63) is energized by yX@, and therefore the output contact (
7) is opened, and the first auxiliary contact (42) is also opened, so that the energization of the tripping coil (4l) is interrupted. In other words, the operation circuit (3) returns to the state before the circuit breaker closing operation.

By the way, when the circuit breaker is closed, if the output contact (7) is closed due to some electrical or mechanical cause, such as chattering due to vibration, the first auxiliary contact (7) is closed even if there is no open phase state. 42) is closed, there is a problem in that power is applied from the power supply P to the tripping coil (41>) via the output contact (7), causing the circuit breaker to open.
If this happens, a power outage will occur on the load side, seriously disrupting the stable supply of electricity. In order to prevent the above-mentioned malfunction, the side of the output contact (7) connected to the power supply P in Fig. 2 is connected to an open-phase detection circuit and an open-phase protection circuit as shown in Fig. 3. Connection point C in (6)
It is being connected to. By connecting in this way, even if the output contact (7) is closed due to vibration, etc., the open phase detection circuit (rFl circuit state) will be tripped via the output contact (7). coil"
41) will not be energized, thus preventing the circuit breaker from opening. However, as shown in Fig. 3, a typical power disconnect switch has a disconnection monitoring circuit (1) in the switchboard circuit (1) in parallel with the trip signal circuit (2), that is, in series with the trip circuit (4). 9
) are provided, (91) and (92) are relays for monitoring disconnection, and (93) is a resistor, which constantly supplies a weak current to the tripping circuit {4) when the circuit breaker is closed,
We are monitoring disconnections. To prevent the tripping coil (4l) from operating due to the weak current and opening the circuit breaker, increase the combined resistance value of the coils of the disconnection monitoring relays (91) and (92) and the resistor (93>). Even if such a disconnection monitoring circuit (9) is installed, if a phase failure occurs in the circuit breaker, the phase failure detection circuit +51 will operate in the same way as above to detect the failure. Phase protection device (6)
This causes the output contact (7) to jump, energizing the tripping circuit (4) and opening the circuit breaker. But 3! ! Even if the open phase detection circuit (51) is opened by opening all phases of the disconnector, the open phase protection circuit (6) is connected to the open circuit monitoring circuit (9L output contact (9L output contact) from the power supply P to the open phase protection circuit (6).
There is a circuit that energizes the power supply N through the output contact (7).
) acts as a self-holding device, and a current larger than the minimum holding current flows through the time-limited electric device (6l) and the auxiliary relay (63), making it impossible to recover. Also, if this recovery is not performed and current flows to the open phase protection circuit (6) via the disconnection monitoring circuit (9), the tripping circuit (4)
Even if a disconnection occurs, the disconnection monitoring circuit (9) is still energized, so the disconnection cannot be detected.Generally, the return voltage of a relay is about 30%, and the voltage between the power supplies P and N is protected by an open-phase protection circuit ( The above problem occurs when the resistive voltage division value applied to 6) exceeds that value. [Problem to be solved by the invention] As described above, the conventional open phase protection translation device suffers from the vibration of the circuit breaker. In order to prevent malfunctions due to chattering, etc., when a phase is missing, the phase-opening protection circuit is activated and the output contact is closed, thereby energizing the tripping circuit via the phase-opening detection circuit. Once the above output contact is closed,
There were problems such as the disconnection monitoring circuit passing power to the phase-loss protection circuit, holding itself in place, and causing the output contact and phase-loss protection circuit to fail to recover. This invention was made to solve the above-mentioned problems, and when a phase failure occurs in the circuit breaker, the phase failure protection circuit operates, and after the circuit breaker opens all phases, the circuit breaker can be reliably restored. The purpose is to obtain an open-phase protection device. [Means for Solving the Problems] An open phase protection device according to the present invention includes a rectifier element provided in series with the output contact in a direction that prevents current flow between the open phase protection circuit and the output contact that is closed by the open phase protection circuit. It is something that

[Function] The phase loss protection device according to the present invention operates because the phase loss protection circuit is activated when a phase loss occurs in the circuit breaker, and after the circuit breaker opens all phases, the rectifier element installed in series with the output contact Second, energization of the path of the disconnection monitoring circuit, the output contact, and the open phase protection circuit is prevented, and therefore the open phase protection circuit and the output contact are reliably restored.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure is a circuit diagram of an open-phase protection device according to an embodiment of the present invention. This is a rectifying element provided on the C side, and is connected in the forward direction from the connection point C toward the output contact (7).Other details are the same as in the case of Fig. 2, so explanations will be omitted. Next, the operation will be explained. When a phase loss occurs in the circuit breaker (not shown), it operates in the same way as in the case of Fig. 2, and the output contact (
7) is closed and the circuit breaker opens all phases. In particular, since the rectifying element 00) is in the forward direction, there is no problem with the above operation. However, after the circuit breaker opens all phases and all phases of the first and second auxiliary contacts <421, (51) open, the disconnection monitoring circuit (9l. output contact (7) and After passing through the open phase protection circuit (6), the power supply N on the negative side
Since a rectifying element 00) is provided in series and in the opposite direction in the circuit leading to the circuit, this prevents the passage of 7TS. Therefore, regardless of the distribution of resistance values in the circuit, the output contact (sword, open phase protection circuit (6)) will definitely return. Note that in Figure 1, if power supplies P and N are swapped In this case, the direction of the rectifying element 00) is reversed from that in FIG. By doing so, energization between the open phase protection circuit (a) and the output contact (7) is blocked, producing the same effect as in the case of FIG. 1. In addition, in the embodiment shown in Fig. 1, the output contact (
Although it is provided on the connection point C side of 7), it may be provided on the tripping circuit (4) side. In this case, it is necessary to provide a rectifying element 0α for each phase.

〔Effect of the invention〕

As described above, according to the present invention, the rectifying element is provided in series with the output contact in the direction of blocking the communication 1E between the open-phase protection fffil path and the output contact that is closed thereby. Therefore, after an open phase occurs in the circuit breaker and the open phase protection circuit operates, and all phases of the breaker are opened, the rectifying element prevents energization of the open circuit monitoring circuit, the above output contact, and the path of the open phase protection circuit. Therefore, the phase loss protection circuit and output contact are effective in reliably returning to normal operation.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of an open phase protection device according to an embodiment of the present invention, and FIGS. 2 and 3 are circuit diagrams of conventional open phase protection devices, respectively. On the diagram! 3, 0) is a trip circuit, (the phrase is a phase loss detection circuit, (6) is a phase loss protection circuit, (7) is an output contact, (9) is a disconnection monitoring circuit, and 001 is a rectifier. , the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] A tripping circuit for a polyphase circuit breaker having a drive device for each phase, a disconnection monitoring circuit connected in series with this tripping circuit to monitor disconnection in the tripping circuit, and when an open phase occurs in the polyphase circuit breaker. a phase-opening detection circuit that operates when the phase-opening detection circuit operates; a phase-opening protection circuit that operates when the phase-opening detection circuit operates; and a phase-opening protection circuit that closes when the phase-opening protection circuit operates and passes through the phase-opening detection circuit to the tripping circuit. A circuit breaker comprising an output contact for energizing a circuit, characterized in that a rectifying element is connected in series with the output contact in a direction that prevents energization between the output contact and the open-phase protection circuit. Text protection device.